feat: basic modal ui

3 files changed, 372 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..7b58d09
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/todo
+todo.dSYM/
+tests/
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..0a5bc8d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,50 @@
+CC := clang
+STD := c17
+
+DEBUG ?= 1
+SANITIZE ?= 1
+
+CFLAGS := -std=$(STD)          \
+          -Wall                \
+          -Wextra              \
+          -Wshadow             \
+          -Wpedantic           \
+          -Wconversion         \
+          -Wstrict-prototypes  \
+          -Wsign-conversion    \
+          -Wmissing-prototypes
+
+ifeq ($(DEBUG),1)
+CFLAGS += -g -fno-omit-frame-pointer
+else
+CFLAGS += -O2
+endif
+
+ifeq ($(SANITIZE),1)
+CFLAGS += -fsanitize=address,undefined
+LDFLAGS += -fsanitize=address,undefined
+endif
+
+TARGET := todo
+SRC := todo.c
+
+PREFIX ?= /usr/local
+bindir := $(DESTDIR)$(PREFIX)/bin
+
+all: $(TARGET)
+
+$(TARGET): $(SRC)
+	$(CC) $(CFLAGS) $< -o $@ $(LDFLAGS)
+
+clean:
+	rm -rf $(TARGET) $(TARGET).dSYM
+
+install:
+	make DEBUG=0 SANITIZE=0 clean all
+	install -d $(bindir)
+	install -m 755 $(TARGET) $(bindir)/$(TARGET)
+
+uninstall:
+	rm -f $(bindir)/$(TARGET)
+
+.PHONY: all clean install uninstall
diff --git a/todo.c b/todo.c
new file mode 100644
index 0000000..802c705
--- /dev/null
+++ b/todo.c
@@ -0,0 +1,319 @@
+/*
+ * todo - a little modal todo list.
+ *
+ * Author:  hachem <im@hachem.wtf>
+ * Version: 0.1.0
+ */
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+#include <unistd.h>
+
+#define todo_program "todo"
+#define todo_version "0.1.0"
+
+#define max_items 4096
+#define max_text  256
+
+struct Item
+{
+    int done;
+    char text[max_text];
+};
+
+struct List
+{
+    struct Item items[max_items];
+    int count;
+};
+
+enum Mode
+{
+    mode_normal
+};
+
+static const char* mode_name(enum Mode mode)
+{
+    switch (mode)
+    {
+        case mode_normal: return "NORMAL";
+    }
+
+    return "?";
+}
+
+static void todo_path(char* buf, size_t size)
+{
+    const char* env = getenv("TODO_FILE");
+
+    if (env != NULL && env[0] != '\0')
+    {
+        (void) snprintf(buf, size, "%s", env);
+        return;
+    }
+
+    const char* home = getenv("HOME");
+
+    (void) snprintf(buf, size, "%s/.todo.txt", home != NULL ? home : ".");
+}
+
+static void strip_newline(char* s)
+{
+    size_t len = strlen(s);
+
+    while (len > 0 && (s[len - 1] == '\n' || s[len - 1] == '\r'))
+        s[--len] = '\0';
+}
+
+/* read the list file. each line is "[ ] text" or "[x] text"; anything else is
+ * treated as an undone item so hand-edited files still load. */
+static void load(struct List* list, const char* path)
+{
+    list->count = 0;
+
+    FILE* file = fopen(path, "r");
+
+    if (file == NULL)
+        return;
+
+    char line[max_text + 8];
+
+    while (list->count < max_items && fgets(line, sizeof line, file) != NULL)
+    {
+        strip_newline(line);
+
+        int done = 0;
+        char* text = line;
+
+        if (line[0] == '[' && line[1] != '\0' && line[2] == ']')
+        {
+            done = line[1] == 'x' || line[1] == 'X';
+            text = line + 3;
+
+            while (*text == ' ')
+                text++;
+        }
+
+        if (*text == '\0')
+            continue;
+
+        struct Item* item = &list->items[list->count++];
+        item->done = done;
+        (void) snprintf(item->text, sizeof item->text, "%s", text);
+    }
+
+    (void) fclose(file);
+}
+
+static void save(const struct List* list, const char* path)
+{
+    FILE* file = fopen(path, "w");
+
+    if (file == NULL)
+        return;
+
+    for (int i = 0; i < list->count; i++)
+        (void) fprintf(file, "[%c] %s\n", list->items[i].done ? 'x' : ' ', list->items[i].text);
+
+    (void) fclose(file);
+}
+
+static struct termios saved_termios;
+
+static void restore_terminal(void)
+{
+    (void) tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_termios);
+    (void) write(STDOUT_FILENO, "\x1b[?25h\x1b[?1049l", 14);
+}
+
+static void on_signal(int signum)
+{
+    (void) signum;
+    exit(EXIT_SUCCESS);
+}
+
+static int enter_raw_mode(void)
+{
+    if (!isatty(STDIN_FILENO))
+    {
+        (void) fprintf(stderr, "%s: not a terminal\n", todo_program);
+        return -1;
+    }
+
+    if (tcgetattr(STDIN_FILENO, &saved_termios) != 0)
+        return -1;
+
+    struct termios raw = saved_termios;
+    raw.c_lflag &= ~((tcflag_t) (ICANON | ECHO | ISIG));
+    raw.c_cc[VMIN] = 1;
+    raw.c_cc[VTIME] = 0;
+
+    if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) != 0)
+        return -1;
+
+    (void) atexit(restore_terminal);
+    (void) signal(SIGINT, on_signal);
+    (void) signal(SIGTERM, on_signal);
+
+    (void) write(STDOUT_FILENO, "\x1b[?1049h\x1b[?25l", 14);
+
+    return 0;
+}
+
+static int screen_rows(void)
+{
+    struct winsize ws;
+
+    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_row > 0)
+        return ws.ws_row;
+
+    return 24;
+}
+
+static void render(const struct List* list, int cursor, int scroll, enum Mode mode)
+{
+    int rows = screen_rows();
+    int visible = rows - 1;
+
+    if (visible < 1)
+        visible = 1;
+
+    char buf[64 * 1024];
+    int n = 0;
+
+    n += snprintf(buf + n, sizeof buf - (size_t) n, "\x1b[H");
+
+    for (int row = 0; row < visible; row++)
+    {
+        int i = scroll + row;
+
+        if (i >= list->count)
+        {
+            n += snprintf(buf + n, sizeof buf - (size_t) n, "\x1b[K\r\n");
+            continue;
+        }
+
+        const struct Item* item = &list->items[i];
+        const char* highlight = i == cursor ? "\x1b[7m" : "";
+        const char* box = item->done ? "\x1b[32m[x]\x1b[0m" : "[ ]";
+        const char* dim = item->done ? "\x1b[2m" : "";
+
+        n += snprintf(buf + n, sizeof buf - (size_t) n,
+                      "%s %s %s%s\x1b[0m\x1b[K\r\n", highlight, box, dim, item->text);
+    }
+
+    int done = 0;
+
+    for (int i = 0; i < list->count; i++)
+        done += list->items[i].done;
+
+    n += snprintf(buf + n, sizeof buf - (size_t) n,
+                  "\x1b[2m-- %s --  %d/%d done\x1b[0m\x1b[K\x1b[J", mode_name(mode), done, list->count);
+
+    (void) write(STDOUT_FILENO, buf, (size_t) n);
+}
+
+static int normal_key(struct List* list, const char* path, int* cursor, char c)
+{
+    switch (c)
+    {
+        case 'q':
+            return 0;
+
+        case 'j':
+            (*cursor)++;
+            break;
+
+        case 'k':
+            (*cursor)--;
+            break;
+
+        case ' ':
+        case 'x':
+            if (*cursor >= 0 && *cursor < list->count)
+            {
+                list->items[*cursor].done = !list->items[*cursor].done;
+                save(list, path);
+            }
+
+            break;
+
+        default:
+            break;
+    }
+
+    return 1;
+}
+
+static void run(struct List* list, const char* path)
+{
+    if (enter_raw_mode() != 0)
+        exit(EXIT_FAILURE);
+
+    enum Mode mode = mode_normal;
+    int cursor = 0;
+    int scroll = 0;
+
+    for (;;)
+    {
+        int visible = screen_rows() - 1;
+
+        if (visible < 1)
+            visible = 1;
+
+        if (cursor >= list->count)
+            cursor = list->count - 1;
+
+        if (cursor < 0)
+            cursor = 0;
+
+        if (cursor < scroll)
+            scroll = cursor;
+
+        if (cursor >= scroll + visible)
+            scroll = cursor - visible + 1;
+
+        render(list, cursor, scroll, mode);
+
+        char c;
+
+        if (read(STDIN_FILENO, &c, 1) != 1)
+            break;
+
+        int keep = 1;
+
+        switch (mode)
+        {
+            case mode_normal:
+                keep = normal_key(list, path, &cursor, c);
+                break;
+        }
+
+        if (!keep)
+            break;
+    }
+}
+
+int main(void)
+{
+    char path[4096];
+    todo_path(path, sizeof path);
+
+    struct List* list = malloc(sizeof *list);
+
+    if (list == NULL)
+    {
+        (void) fprintf(stderr, "%s: out of memory\n", todo_program);
+        return EXIT_FAILURE;
+    }
+
+    load(list, path);
+    run(list, path);
+    free(list);
+
+    return EXIT_SUCCESS;
+}